Do IUDs Help Prevent Cervical Cancer?

A new study suggests the device may do more than prevent pregnancy. But is it safe for all women?

The second most-popular form of birth control in the world already has an impressive list of potential benefits.

It’s tied with female sterilization as the most reliable and effective form of birth control.

It’s long-lasting.

It’s instantly reversible.

It offers women options that can either reduce bleeding and cramping through very low doses of hormones or a completely hormone-free method.

And now, according to a study in The Lancet Oncology, there is evidence that suggests women who have ever used an intrauterine device (IUD) have a statistically significant reduction in the risk of developing cervical cancer.

The Lancet study examined the incidence of three forms of cervical cancer among more than 20,000 IUD users worldwide, assessing data from 26 previous studies. It found that among women whose device had been in place for one year or more, the odds of developing the most common form of cervical cancer were lowered by 44 percent. Two other forms of cancer were reduced by 54 percent in IUD users than non-IUD users. While the mechanism for this effect is not yet understood, researchers suggest the IUD may stimulate an immune response that prevents the development of cervical cancer.

Gaining popularity, getting further from a troubled past

“I find in my own practice that the IUD is gaining popularity among younger women,” says Scripps obstetrician and gynecologist Sudi Moein, MD.

While use of the IUD in America trails well behind Europe, Asia and Africa, the numbers of women in the US choosing the method have been rising in recent years. While only 2 percent of American women relied on IUDs in 2002, by 2010 that number had risen to nearly 5 percent.

A generation ago, a heavily marketed form of the device, the Dalkon shield, was found to have a design flaw—a braided string—that allowed bacteria to “wick” into a woman’s uterus and contributed to numerous cases of pelvic inflammatory disease, infection, septic pregnancy and even death. After years of controversy, the shield was pulled from the U.S. market in 1980. But the damage was done. American use of IUDs plunged.

“There are still a lot of gaps in awareness and understanding about the device here in America,” says Dr. Moein. “Unfortunately, the media played a role in that—and not necessarily because they were reporting the scientific facts.” The rest of the world continued to use the device, and it has steadily grown in popularity as a form of family planning.

Despite its 99 percent rate of effectiveness, IUDs remain relatively uncommon in the U.S. By comparison, the birth control pill is only 97 percent effective with imperfect use, and condoms fail to prevent pregnancy up to 12 percent of the time.

There are two varieties of modern IUD in use in the U.S. Both consist of a T-shaped piece of plastic that is inserted by a gynecologist, nurse practitioner or midwife. The older form, called “Paragard,” which can prevent pregnancy for up to 10 years, includes copper wire wrapped around the arms of the T. Copper is toxic to sperm and also makes the uterus hostile to implantation.

The newer form, marketed under the name “Mirena,” releases very low doses of a hormone called “progestin” over time. This device remains effective for up to five years and may have additional benefits as well.

“Many of my patients have experienced far less cramping and reduced bleeding with the hormonal IUD,” says Dr. Moein. In addition, the Mirena has been studied and approved by the FDA as an effective treatment for endometriosis.

An option for some, but not all

Dr. Moein strongly cautions that IUDs do not offer protection against the virus that causes cervical cancer (HPV), or other sexually transmitted diseases (STDs). “Women who have multiple sexual partners need to understand that the IUD only protects against pregnancy. It does not prevent the transmission of STDs. If a woman is not in a monogamous relationship with a partner whose STD status is known, she should definitely use additional barrier protection against such pathogens as HIV, syphilis, gonorrhea, Chlamydia, and HPV.”

Until 2005, the Food and Drug Administration (FDA) only recommended IUDs for women who had already had children, due to lingering concerns about infertility due to infection based on the flawed Dalkon shield. Based on newer studies that proved the safety and efficacy of the new generation of devices, however, FDA revised its recommendations to include all women, no matter their age or reproductive history.

Beginning in 2013, the Affordable Care Act will require all insurance companies to cover all forms of birth control as preventive care, which may boost the number of women choosing IUDs even more.

“The IUD has come a long way since the 1970s and 1980s,” says Dr. Moein. “It is something more women are taking a look at. While the Lancet cervical cancer study is not a reason in and of itself to choose an IUD, it adds another piece of data to the picture.”

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